Spring gRPC Example

This repository contains two separate Spring Boot projects demonstrating a gRPC server and client. It showcases the four main types of gRPC communication patterns: Unary RPC, Server Streaming RPC, Client Streaming RPC, and Bidirectional Streaming RPC.

Projects

grpc-server

This project contains the gRPC server implementation. It includes services such as UnaryService, ServerStreamingService, ClientStreamingService, and BidirectionalStreamingService.

grpc-client

This project contains the gRPC client implementation which interacts with the gRPC server using the mentioned services.

Prerequisites

• Java 17
• Maven

Running the Projects

Running the Server

1. Navigate to the grpc-server directory:

   cd spring-grpc-example/grpc-server

2. Run the server application:

   ./mvnw spring-boot:run

3. You should see logs indicating the server has started on the specified port:

   🚀 gRPC Server has successfully started on port 9090.
   

Running the Client

1. Open a new terminal and navigate to the grpc-client directory:

   cd spring-grpc-example/grpc-client

2. Run the client application:

   ./mvnw spring-boot:run

3. You should see logs indicating the client has initialized the system and started the different gRPC interactions:

   Unary response: Unary response: Performing unary call...
   Sent client message: Client message 1
   Received from server streaming: Server streaming response 1: Performing server streaming call...
   Received from bidirectional streaming: Response: Ping
   

Project Structure

• grpc-server: Contains the gRPC server code.
• grpc-client: Contains the gRPC client code.
• proto/unary.proto: Protocol Buffers definition file used by both server and client for the unary service.
• proto/server_streaming.proto: Protocol Buffers definition file used by both server and client for the server streaming service.
• proto/client_streaming.proto: Protocol Buffers definition file used by both server and client for the client streaming service.
• proto/bidirectional_streaming.proto: Protocol Buffers definition file used by both server and client for the bidirectional streaming service.

Example Protobuf Definitions

Unary Service (unary.proto)

syntax = "proto3";

option java_multiple_files = true;
option java_package = "com.example.grpc";
option java_outer_classname = "UnaryProto";

package unary;

// The Unary service definition.
service UnaryService {
  rpc UnaryCall (UnaryRequest) returns (UnaryResponse);
}

// The request message containing the unary call message.
message UnaryRequest {
  string message = 1;
}

// The response message containing the unary call response.
message UnaryResponse {
  string message = 1;
}

Server Streaming Service (server_streaming.proto)

syntax = "proto3";

option java_multiple_files = true;
option java_package = "com.example.grpc";
option java_outer_classname = "ServerStreamingProto";

package serverstreaming;

// The Server Streaming service definition.
service ServerStreamingService {
  rpc ServerStreamingCall (ServerStreamingRequest) returns (stream ServerStreamingResponse);
}

// The request message containing the server streaming call message.
message ServerStreamingRequest {
  string message = 1;
}

// The response message containing the server streaming response.
message ServerStreamingResponse {
  string message = 1;
}

Dependencies

• Spring Boot 3
• gRPC
• Protocol Buffers

Contributing

Feel free to fork this repository and contribute by submitting a pull request.

License

This project is licensed under the MIT License.